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Zhang J, Yang XY, Chen J, Zhou Q, Pan G, Wang Y, Luo W, Hou J, Bao H, Xu G, Tang G, Bai H, Yu R. A Poly(amino acid)-Based Nanomedicine Strategy: Telomere-Telomerase Axis Targeting and Magnetic Resonance Imaging in Hepatocellular Carcinoma Treatment. NANO LETTERS 2024; 24:8351-8360. [PMID: 38916238 DOI: 10.1021/acs.nanolett.4c01767] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/26/2024]
Abstract
Targeting telomere maintenance has emerged as a promising strategy for hepatocellular carcinoma (HCC) treatment. However, given the duality of the telomere-telomerase axis in telomere maintenance, a comprehensive strategy is urgently needed. Herein, we develop a poly(amino acid) (D-PAAs)-based strategy for spatiotemporal codelivery of telomerase inhibitor, BIBR1523, and AKT inhibitor, isobavachalcone. By leveraging D-PAAs' modifiability, we synthesize polymer-inhibitor conjugates (PB and PI) and a folic acid-decorated tumor-targeting vector (PF). These building blocks undergo micellization to fabricate a codelivery nanomedicine (P-BI@P-FA) by exploiting D-PAAs' noncovalent assembly. P-BI@P-FA improves the pharmacokinetics, tumor selectivity, and bioavailability of small molecule inhibitors and initiates a dual telomere-specific inhibition by combining telomerase deactivation with telomere disruption. Furthermore, a hybrid tumor-targeting magnetic nanosystem is designed using D-PAAs and manganese dioxide to showcase magnetic resonance imaging capacities. Our D-PAAs-based strategy addresses the pressing need for telomere-specific HCC treatment while allowing for diagnostic application, presenting a promising avenue for nanomedicine design.
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Affiliation(s)
- Jinguo Zhang
- Department of Radiology, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310009, People's Republic of China
| | - Xiao-Yan Yang
- Department of Radiology, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310009, People's Republic of China
| | - Jiayi Chen
- Department of Chemistry, Zhejiang University, Hangzhou 310028, People's Republic of China
| | - Qiaomei Zhou
- Department of Radiology, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310009, People's Republic of China
| | - Guohua Pan
- Department of Chemistry, Zhejiang University, Hangzhou 310028, People's Republic of China
| | - Yining Wang
- Department of Radiology, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310009, People's Republic of China
| | - Wangping Luo
- Department of Radiology, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310009, People's Republic of China
| | - Jue Hou
- Department of Chemistry, Zhejiang University, Hangzhou 310028, People's Republic of China
| | - Hanxiao Bao
- Department of Chemistry, Zhejiang University, Hangzhou 310028, People's Republic of China
| | - Guoqiao Xu
- Department of Chemistry, Zhejiang University, Hangzhou 310028, People's Republic of China
| | - Guping Tang
- Department of Radiology, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310009, People's Republic of China
- Department of Chemistry, Zhejiang University, Hangzhou 310028, People's Republic of China
| | - Hongzhen Bai
- Department of Chemistry, Zhejiang University, Hangzhou 310028, People's Republic of China
| | - Risheng Yu
- Department of Radiology, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310009, People's Republic of China
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Gholami L, Mahmoudi A, Kazemi Oskuee R, Malaekeh-Nikouei B. An overview of polyallylamine applications in gene delivery. Pharm Dev Technol 2022; 27:714-724. [PMID: 35880621 DOI: 10.1080/10837450.2022.2107014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
A chief objective of gene transportation studies is to manipulate clinically accepted carriers that can be utilized to combat incurable diseases. Despite various strategies, efficiency and application of these vectors have been hindered, owing to different obstacles. Polyallylamine (PAA) is a synthetic water-soluble, weak base cationic polymer with different properties that could be administrated as an ideal candidate for biomedical applications such as gene delivery, drug delivery, or even tissue engineering. However, some intrinsic properties of this polymer limit its application. The two associated problems with the use of PAA in gene delivery are low transfection efficiency (because of low buffering capacity) and cytotoxic effects attributed to intense cationic character. Most of the strategies for structural modification of the PAA structure have focused on introducing hydrophobic groups to the polymeric backbone that target both cytotoxicity and transfection. In this perspective, we concentrate on PAA as a gene delivery vehicle and the existing approaches for modification of this cationic polymer to give insight to researchers for exploitation of PAA as an efficient carrier in biomedical applications.
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Affiliation(s)
- Leila Gholami
- Nanotechnology Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Asma Mahmoudi
- Nanotechnology Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Reza Kazemi Oskuee
- Applied Biomedical Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Bizhan Malaekeh-Nikouei
- Nanotechnology Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran
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Odunze U, O'Brien F, Godfrey L, Schätzlein A, Uchegbu I. Unusual Enthalpy Driven Self Assembly at Room Temperature with Chitosan Amphiphiles. Pharm Nanotechnol 2019; 7:57-71. [PMID: 30854985 PMCID: PMC6691848 DOI: 10.2174/2211738507666190311123401] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Revised: 02/25/2019] [Accepted: 02/25/2019] [Indexed: 01/26/2023]
Abstract
Background: GCPQ (N-palmitoyl-N-monomethyl-N,N-dimethyl-N,N,N-trime-thyl-6-O-glycolchitosan) is a self-assembling polymer being investigated as a pharmaceu-tical nano-carrier. GCPQ nanoparticles shuttle drugs across biological barriers, improving drug performance. The exact chemistry of GCPQ is varied by the relative proportion of hydrophobic (N-palmitoyl) and hydrophilic (quaternary ammonium) groups and molecu-lar weight. Objective: We hypothesised that the thermodynamics of self-assembly is controlled by the polymer molecular weight and hydrophobicity. Method: The thermodynamics of self-assembly was investigated using isothermal calo-rimetry. Results: GCPQs (Mw = 8-15 kDa) formed micellar aggregates at critical micellar concen-trations of 1-2.4 μM at 25°C and micellisation was unusually enthalpy driven. There was a positive correlation between ΔHmic and mole% quaternary groups (Q): ΔHmic = 3.8 Q-159 (r2 = 0.93) and a negative correlation between ΔHmic and molecular weight (Mw): ΔHmic = -13.5 Mw-26.3 (r2 = 0.99). Conclusion: These findings provide insights into the positive drivers of stable self-assemblies, namely hydrophobicity and molecular weight, as both hydrophobicity and molecular weight are associated with an increased enthalpy contribution to micellisation.
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Affiliation(s)
- Uchechukwu Odunze
- School of Pharmacy, University College London, 29-39 Brunswick Square, London WC1N 1AX, United Kingdom
| | - Fionn O'Brien
- School of Pharmacy, University College London, 29-39 Brunswick Square, London WC1N 1AX, United Kingdom
| | - Lisa Godfrey
- School of Pharmacy, University College London, 29-39 Brunswick Square, London WC1N 1AX, United Kingdom
| | - Andreas Schätzlein
- School of Pharmacy, University College London, 29-39 Brunswick Square, London WC1N 1AX, United Kingdom.,Nanomerics, New Bridge Street House, 30-34 New Bridge Street, London, EC4V 6BJ, United Kingdom
| | - Ijeoma Uchegbu
- School of Pharmacy, University College London, 29-39 Brunswick Square, London WC1N 1AX, United Kingdom.,Nanomerics, New Bridge Street House, 30-34 New Bridge Street, London, EC4V 6BJ, United Kingdom
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Ibie C, Knott R, Thompson C. Complexation of novel thiomers and insulin to protect against in vitro enzymatic degradation – towards oral insulin delivery. Drug Dev Ind Pharm 2018; 45:67-75. [DOI: 10.1080/03639045.2018.1517776] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- C.O. Ibie
- School of Pharmacy and Life Sciences, Robert Gordon University, Garthdee Road, Aberdeen, UK
| | - R.M. Knott
- School of Pharmacy and Life Sciences, Robert Gordon University, Garthdee Road, Aberdeen, UK
| | - C.J. Thompson
- School of Pharmacy and Life Sciences, Robert Gordon University, Garthdee Road, Aberdeen, UK
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Klein PM, Klinker K, Zhang W, Kern S, Kessel E, Wagner E, Barz M. Efficient Shielding of Polyplexes Using Heterotelechelic Polysarcosines. Polymers (Basel) 2018; 10:E689. [PMID: 30966723 PMCID: PMC6404158 DOI: 10.3390/polym10060689] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Revised: 06/13/2018] [Accepted: 06/17/2018] [Indexed: 11/16/2022] Open
Abstract
Shielding agents are commonly used to shield polyelectrolyte complexes, e.g., polyplexes, from agglomeration and precipitation in complex media like blood, and thus enhance their in vivo circulation times. Since up to now primarily poly(ethylene glycol) (PEG) has been investigated to shield non-viral carriers for systemic delivery, we report on the use of polysarcosine (pSar) as a potential alternative for steric stabilization. A redox-sensitive, cationizable lipo-oligomer structure (containing two cholanic acids attached via a bioreducible disulfide linker to an oligoaminoamide backbone in T-shape configuration) was equipped with azide-functionality by solid phase supported synthesis. After mixing with small interfering RNA (siRNA), lipopolyplexes formed spontaneously and were further surface-functionalized with polysarcosines. Polysarcosine was synthesized by living controlled ring-opening polymerization using an azide-reactive dibenzo-aza-cyclooctyne-amine as an initiator. The shielding ability of the resulting formulations was investigated with biophysical assays and by near-infrared fluorescence bioimaging in mice. The modification of ~100 nm lipopolyplexes was only slightly increased upon functionalization. Cellular uptake into cells was strongly reduced by the pSar shielding. Moreover, polysarcosine-shielded polyplexes showed enhanced blood circulation times in bioimaging studies compared to unshielded polyplexes and similar to PEG-shielded polyplexes. Therefore, polysarcosine is a promising alternative for the shielding of non-viral, lipo-cationic polyplexes.
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Affiliation(s)
- Philipp Michael Klein
- Department of Pharmacy, Ludwig-Maximilians-Universität (LMU) Munich, Pharmaceutical Biotechnology, Butenandtstrasse 5-13, D-81377 Munich, Germany.
| | - Kristina Klinker
- Institute of Organic Chemistry, Johannes Gutenberg University, Duesbergweg 10-14, D-55128 Mainz, Germany.
- Graduate School Materials Science in Mainz, Staudinger Weg 9, 55128 Mainz, Germany.
| | - Wei Zhang
- Department of Pharmacy, Ludwig-Maximilians-Universität (LMU) Munich, Pharmaceutical Biotechnology, Butenandtstrasse 5-13, D-81377 Munich, Germany.
| | - Sarah Kern
- Department of Pharmacy, Ludwig-Maximilians-Universität (LMU) Munich, Pharmaceutical Biotechnology, Butenandtstrasse 5-13, D-81377 Munich, Germany.
| | - Eva Kessel
- Department of Pharmacy, Ludwig-Maximilians-Universität (LMU) Munich, Pharmaceutical Biotechnology, Butenandtstrasse 5-13, D-81377 Munich, Germany.
| | - Ernst Wagner
- Department of Pharmacy, Ludwig-Maximilians-Universität (LMU) Munich, Pharmaceutical Biotechnology, Butenandtstrasse 5-13, D-81377 Munich, Germany.
- Nanosystems Initiative Munich, Schellingstraße 4, D-80799 Munich, Germany.
| | - Matthias Barz
- Institute of Organic Chemistry, Johannes Gutenberg University, Duesbergweg 10-14, D-55128 Mainz, Germany.
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Influence of Defined Hydrophilic Blocks within Oligoaminoamide Copolymers: Compaction versus Shielding of pDNA Nanoparticles. Polymers (Basel) 2017; 9:polym9040142. [PMID: 30970822 PMCID: PMC6432433 DOI: 10.3390/polym9040142] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Revised: 04/07/2017] [Accepted: 04/11/2017] [Indexed: 01/07/2023] Open
Abstract
Cationic polymers are promising components of the versatile platform of non-viral nucleic acid (NA) delivery agents. For a successful gene delivery system, these NA vehicles need to comprise several functionalities. This work focuses on the modification of oligoaminoamide carriers with hydrophilic oligomer blocks mediating nanoparticle shielding potential, which is necessary to prevent aggregation or dissociation of NA polyplexes in vitro, and hinder opsonization with blood components in vivo. Herein, the shielding agent polyethylene glycol (PEG) in three defined lengths (12, 24, or 48 oxyethylene repeats) is compared with two peptidic shielding blocks composed of four or eight repeats of sequential proline-alanine-serine (PAS). With both types of shielding agents, we found opposing effects of the length of hydrophilic segments on shielding and compaction of formed plasmid DNA (pDNA) nanoparticles. Two-arm oligoaminoamides with 37 cationizable nitrogens linked to 12 oxyethylene units or four PAS repeats resulted in very compact 40⁻50 nm pDNA nanoparticles, whereas longer shielding molecules destabilize the investigated polyplexes. Thus, the balance between sufficiently shielded but still compact and stable particles can be considered a critical optimization parameter for non-viral nucleic acid vehicles based on hydrophilic-cationic block oligomers.
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Zhuang J, Garzoni M, Torres DA, Poe A, Pavan GM, Thayumanavan S. Programmable Nanoassemblies from Non-Assembling Homopolymers Using Ad Hoc Electrostatic Interactions. Angew Chem Int Ed Engl 2017; 56:4145-4149. [PMID: 28294469 PMCID: PMC5543410 DOI: 10.1002/anie.201611688] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 01/23/2017] [Indexed: 12/21/2022]
Abstract
Robust nanostructures were obtained from polymers that otherwise do not assemble by using a novel approach based on electrostatic self-assembly. The essence of this strategy involves the use of divalent counterions to temporarily perturb the packing features of the ionic groups in a homopolymer, which results in a vesicle-like structure that is captured in situ through a simple crosslinking reaction. The fidelity of the assembly has been tested for molecular transport across the nanomembrane, both for the molecules encapsulated in the lumen and for those trapped in the membrane itself. The membranes are addressable for robust multifunctionalization of their surfaces and for tunable transmembrane molecular transport.
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Affiliation(s)
- Jiaming Zhuang
- Department of Chemistry, University of Massachusetts Amherst, Amherst, MA, 01003, USA
| | - Matteo Garzoni
- Department of Innovative Technologies, University of Applied Sciences and Arts of Southern Switzerland, Galleria 2, Via Cantonale 2C, Manno, 6928, Switzerland
| | - Diego Amado Torres
- Department of Chemistry, University of Massachusetts Amherst, Amherst, MA, 01003, USA
| | - Ambata Poe
- Department of Chemistry, University of Massachusetts Amherst, Amherst, MA, 01003, USA
| | - Giovanni M Pavan
- Department of Innovative Technologies, University of Applied Sciences and Arts of Southern Switzerland, Galleria 2, Via Cantonale 2C, Manno, 6928, Switzerland
| | - S Thayumanavan
- Department of Chemistry, University of Massachusetts Amherst, Amherst, MA, 01003, USA
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Zhuang J, Garzoni M, Torres DA, Poe A, Pavan GM, Thayumanavan S. Programmable Nanoassemblies from Non‐Assembling Homopolymers Using Ad Hoc Electrostatic Interactions. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201611688] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Jiaming Zhuang
- Department of Chemistry University of Massachusetts Amherst Amherst MA 01003 USA
| | - Matteo Garzoni
- Department of Innovative Technologies University of Applied Sciences and Arts of Southern Switzerland Galleria 2, Via Cantonale 2C Manno 6928 Switzerland
| | - Diego Amado Torres
- Department of Chemistry University of Massachusetts Amherst Amherst MA 01003 USA
| | - Ambata Poe
- Department of Chemistry University of Massachusetts Amherst Amherst MA 01003 USA
| | - Giovanni M. Pavan
- Department of Innovative Technologies University of Applied Sciences and Arts of Southern Switzerland Galleria 2, Via Cantonale 2C Manno 6928 Switzerland
| | - S. Thayumanavan
- Department of Chemistry University of Massachusetts Amherst Amherst MA 01003 USA
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Riabtseva A, Mitina N, Grytsyna I, Boiko N, Garamus VM, Stryhanyuk H, Stoika R, Zaichenko A. Functional micelles formed by branched polymeric surfactants: Synthesis, characteristics, and application as nanoreactors and carriers. Eur Polym J 2016. [DOI: 10.1016/j.eurpolymj.2016.01.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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10
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Zheng Z, Liu C, Qiao W. pH-Responsive and CO2-responsive vesicles can be formed byN-decylimidazole. EUR J LIPID SCI TECH 2015. [DOI: 10.1002/ejlt.201400429] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Zhibo Zheng
- State Key Laboratory of Fine Chemicals; School of Chemical Engineering; Dalian University of Technology; Dalian P. R. China
| | - Chenyu Liu
- State Key Laboratory of Fine Chemicals; School of Chemical Engineering; Dalian University of Technology; Dalian P. R. China
| | - Weihong Qiao
- State Key Laboratory of Fine Chemicals; School of Chemical Engineering; Dalian University of Technology; Dalian P. R. China
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Zhao L, Li N, Wang K, Shi C, Zhang L, Luan Y. A review of polypeptide-based polymersomes. Biomaterials 2013; 35:1284-301. [PMID: 24211077 DOI: 10.1016/j.biomaterials.2013.10.063] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2013] [Accepted: 10/20/2013] [Indexed: 12/11/2022]
Abstract
Self-assembled systems from biodegradable amphiphilic polymers at the nanometer scale, such as nanotubes, nanoparticles, polymer micelles, nanogels, and polymersomes, have attracted much attention especially in biomedical fields. Among these nano-aggregates, polymersomes have attracted tremendous interests as versatile carriers due to their colloidal stability, tunable membrane properties and ability of encapsulating or integrating a broad range of drugs and molecules. Biodegradable block polymers, especially aliphatic polyesters such as polylactide, polyglycolide and poly (ε-caprolactone) have been widely used as biomedical materials for a long time to well fit the requirement of biomedical drug carriers. To have a precise control of the aggregation behavior of nano-aggregates, the more ordered polypeptide has been used to self-assemble into the drug carriers. In this review we focus on the study of polymersomes which also named pepsomes formed by polypeptide-based copolymers and attempt to clarify the polypeptide-based polymersomes from following aspects: synthesis and characterization of the polypeptide-based copolymers, preparation, multifunction and application of polypeptide-based polymersomes.
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Affiliation(s)
- Lanxia Zhao
- School of Pharmaceutical Science, Shandong University, 44 West Wenhua Road, Jinan, Shandong Province 250012, PR China
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Zhu L, Zhao L, Qu X, Yang Z. pH-sensitive polymeric vesicles from coassembly of amphiphilic cholate grafted poly(L-lysine) and acid-cleavable polymer-drug conjugate. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:11988-11996. [PMID: 22845809 DOI: 10.1021/la3015767] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Herein we report a coassembly method toward the preparation of pH-sensitive polymeric vesicular aggregates, using comb-shaped amphiphilic polymers, i.e., cholate grafted poly(L-lysine) (PLL-CA), with an amphiphilic poly(ethylene glycol)-doxorubicin conjugate (PEG-DOX). Because the drug conjugate includes a low-pH labile bond, i.e., benzoic imine, the permeability of the coassembled polymeric vesicles can be tuned by changing either the PLL-CA/PEG-DOX weight ratio or the environmental pH from 7.4 to 6.5. Furthermore, at lower pH values such as 5.0, the vesicles destabilize. The pH sensitivity leads to enhanced uptake of the vesicles by cancer cells (MCF-7) under a condition close to the extracellular environment of solid tumor (pH = 6.5) and subsequent efficient endosome escape after the endocytosis.
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Affiliation(s)
- Lijun Zhu
- State Key Laboratory of Polymer Physics and Chemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
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A review on comb-shaped amphiphilic polymers for hydrophobic drug solubilization. Ther Deliv 2012; 3:59-79. [PMID: 22833933 DOI: 10.4155/tde.11.130] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Comb-shaped amphiphilic polymers are rapidly emerging as an alternative approach to amphiphilic block copolymers for hydrophobic drug solubilization. These polymers consist of a homopolymer or copolymer backbone to which hydrophobic and hydrophilic pendant groups can be grafted resulting in a comb-like architecture. The hydrophobic pendants may consist of homopolymers, copolymers and other low-molecular weight hydrophobic structures. In this review, we focus on hydrophobically modified preformed homopolymers. Comb-shaped amphiphilic polymers possess reduced critical aggregation concentration values compared with traditional surfactant micelles indicating increased stability with decreased disruption experienced on dilution. They have been fabricated with diverse architectures and multifunctional properties such as site-specific targeting and external stimuli-responsive nature. The application of comb-shaped amphiphilic polymers is expanding; here we report on the progress achieved so far in hydrophobic drug solubilization for both intravenous and oral delivery.
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Zhao M, Yuan J, Zheng L. Spontaneous formation of vesicles by N-dodecyl-N-methylpyrrolidinium bromide (C12MPB) ionic liquid and sodium dodecyl sulfate (SDS) in aqueous solution. Colloids Surf A Physicochem Eng Asp 2012. [DOI: 10.1016/j.colsurfa.2012.05.016] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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15
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Lalatsa A, Schätzlein AG, Mazza M, Le TBH, Uchegbu IF. Amphiphilic poly(l-amino acids) — New materials for drug delivery. J Control Release 2012; 161:523-36. [DOI: 10.1016/j.jconrel.2012.04.046] [Citation(s) in RCA: 125] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2012] [Revised: 04/17/2012] [Accepted: 04/18/2012] [Indexed: 01/16/2023]
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Hoskins C, Lin PKT, Tetley L, Cheng WP. Novel fluorescent amphiphilic poly(allylamine) and their supramacromolecular self-assemblies in aqueous media. POLYM ADVAN TECHNOL 2011. [DOI: 10.1002/pat.1962] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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17
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Cheng WP, Thompson C, Ryan SM, Aguirre T, Tetley L, Brayden DJ. In vitro and in vivo characterisation of a novel peptide delivery system: amphiphilic polyelectrolyte-salmon calcitonin nanocomplexes. J Control Release 2010; 147:289-97. [PMID: 20705108 DOI: 10.1016/j.jconrel.2010.07.128] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2010] [Revised: 07/29/2010] [Accepted: 07/31/2010] [Indexed: 11/16/2022]
Abstract
The cationic peptide, salmon calcitonin (sCT) was complexed with the cationic amphiphilic polyelectrolyte, poly(allyl)amine, grafted with palmitoyl and quaternary ammonium moieties at pH 5.0 and 7.4 to yield particulates (sCT-QPa). The complexes were approximately 200 nm in diameter, had zeta potentials ranging from +20 to +50 mV, and had narrow polydispersity indices (PDIs). Differential scanning calorimetry revealed the presence of an interaction between sCT and QPa in the complexes. Electron microscopy confirmed the zeta-size data and revealed a vesicular bilayer structure with an aqueous core. Tyrosine- and Nile red fluorescence indicated that the complexes retained gross physical stability for up to 7 days, but that the pH 5.0 complexes were more stable. The complexes were more resistant to peptidases, serum and liver homogenates compared to free sCT. In vitro bioactivity was measured by cAMP production in T47D cells and the complexes had EC50 values in the nM range. While free sCT was unable to generate cAMP following storage for 7 days, the complexes retained approximately 33% activity. When the complexes were injected intravenously to rats, free and complexed sCT (pH 5.0 and 7.4) but not QPa reduced serum calcium over 120 min. Free and complexed sCT but not QPa also reduced serum calcium over 240 min following intra-jejunal administration. In conclusion, sCT-QPa nanocomplexes that have been synthesised are stable, bioactive and resistant to a range of peptidases. These enhanced features suggest that they may have the potential for improved efficacy when formulated for injected and oral delivery.
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Affiliation(s)
- Woei-Ping Cheng
- School of Pharmacy, University of Hertfordshire, College Lane Hatfield AL10 9AB, UK
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Thompson C, Tetley L, Cheng W. The influence of polymer architecture on the protective effect of novel comb shaped amphiphilic poly(allylamine) against in vitro enzymatic degradation of insulin—Towards oral insulin delivery. Int J Pharm 2010; 383:216-27. [DOI: 10.1016/j.ijpharm.2009.09.018] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2009] [Revised: 09/04/2009] [Accepted: 09/11/2009] [Indexed: 10/20/2022]
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Thompson C, Tetley L, Uchegbu I, Cheng W. The complexation between novel comb shaped amphiphilic polyallylamine and insulin—Towards oral insulin delivery. Int J Pharm 2009; 376:46-55. [DOI: 10.1016/j.ijpharm.2009.04.014] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2009] [Revised: 04/07/2009] [Accepted: 04/08/2009] [Indexed: 11/30/2022]
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Bertin A, Hermes F, Schlaad H. Biohybrid and Peptide-Based Polymer Vesicles. ADVANCES IN POLYMER SCIENCE 2009. [DOI: 10.1007/978-3-642-10479-4_12] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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Thompson CJ, Ding C, Qu X, Yang Z, Uchegbu IF, Tetley L, Cheng WP. The effect of polymer architecture on the nano self-assemblies based on novel comb-shaped amphiphilic poly(allylamine). Colloid Polym Sci 2008. [DOI: 10.1007/s00396-008-1925-8] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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22
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Qu X, Omar L, Le TBH, Tetley L, Bolton K, Chooi KW, Wang W, Uchegbu IF. Polymeric amphiphile branching leads to rare nanodisc shaped planar self-assemblies. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008; 24:9997-10004. [PMID: 18690736 DOI: 10.1021/la8007848] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Self-assembly is fundamental to the biological function of cells and the fabrication of nanomaterials. However, the origin of the shape of various self-assemblies, such as the shape of cells, is not altogether clear. Polymeric, oligomeric, or low molecular weight amphiphiles are a rich source of nanomaterials, and controlling their self-assembly is the route to tailored nanosystems with specific functionalities. Here, we provide direct evidence that a particular molecular architecture, polymeric branching, leads to a rare form of self-assembly, the planar nanodisc. Cholesterol containing self-assemblies formed from amphiphilic linear or branched cetyl poly(ethylenimine) (Mn approximately 1000 Da) or amphiphilic cetyl poly(propylenimine) dendrimer derivatives (Mn approximately 2000 Da) show that branching, by reducing the hydrophilic headgroup area, alters the shape of the self-assemblies transforming closed 60 nm spherical bilayer vesicles to rare 50 nm x 10 nm planar bilayer discs. Increasing the hydrophilic headgroup area, by the inclusion of methoxy poly(ethylene glycol) moieties into the amphiphilic headgroup, transforms the planar discs to 100 nm spherical bilayer vesicles. This study provides insight into the key role played by molecular shape on molecular self-organization into rare nanodiscs.
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Affiliation(s)
- Xiaozhong Qu
- School of Pharmacy, University of London, 29-39 Brunswick Square, London, UK
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23
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Pan H, Kopecková P, Liu J, Wang D, Miller SC, Kopecek J. Stability in plasmas of various species of HPMA copolymer-PGE1 conjugates. Pharm Res 2007; 24:2270-80. [PMID: 17899324 DOI: 10.1007/s11095-007-9449-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2007] [Accepted: 08/28/2007] [Indexed: 10/22/2022]
Abstract
PURPOSE To determine the stability of HPMA copolymer-prostaglandin E(1) (PGE(1)) conjugates in plasmas of different species and to identify the enzymes responsible for the cleavage of the ester bond. METHODS The conjugates were incubated in human, rat, and mouse plasma at 37 degrees C in the presence and absence of specific esterase inhibitors. The released PGE(1) was analyzed using an HPLC assay. To evaluate the effect of the conformation of the conjugate on the rate of PGE(1) release, its structure was modified by the attachment of hydrophobic side chains. RESULTS The rate of PGE(1) release was strongly species dependent. Whereas the conjugate was stable in human plasma, the PGE(1) release in rat or mouse plasma was substantial. In rat plasma, the ester bond cleavage was mainly catalyzed by butyrylcholinesterase; in mouse plasma, in addition to butyrylcholinesterase, carboxylesterase also contributed to the cleavage. The formation of compact polymer coils stabilized the ester bond. CONCLUSIONS HPMA copolymer-PGE(1) conjugates are strong candidates as novel therapeutics for the treatment of osteoporosis. The observed species differences in plasma stability of ester bonds are of importance, because the ovariectomized rat model is recommended by the FDA for pre-clinical evaluation.
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Affiliation(s)
- Huaizhong Pan
- Department of Pharmaceutics and Pharmaceutical Chemistry/CCCD, University of Utah, Salt Lake City, Utah 84112, USA
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24
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Shenoy DB, Amiji MM. An overview of condensing and noncondensing polymeric systems for gene delivery. ACTA ACUST UNITED AC 2007; 2007:pdb.top9. [PMID: 21357090 DOI: 10.1101/pdb.top9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
INTRODUCTIONSelf-assembling synthetic vectors for DNA delivery are designed to fulfill several biological functions. They must be able to deliver their genetic payload specifically to the target tissue/cells in a site-specific manner, while protecting the genetic material from degradation by metabolic or immune pathways. Furthermore, they must exhibit minimal toxicity and be proven safe enough for therapeutic use. Ultimately, they must have the capability to express a therapeutic gene for a finite period of time in an appropriate, regulated fashion. The DNA encapsulated in these vectors may be in a condensed or noncondensed form, depending on the nature of the polymer and the technique used for formulating the vector system. The whole process presents many barriers at both tissue and cellular levels. Overcoming these hurdles is the principal objective for efficient polymer-based DNA therapeutics.
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25
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Uchegbu IF. Pharmaceutical nanotechnology: polymeric vesicles for drug and gene delivery. Expert Opin Drug Deliv 2006; 3:629-40. [PMID: 16948558 DOI: 10.1517/17425247.3.5.629] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Improving the therapeutic index of medicines is a goal of drug delivery. Employing nanosystems that control drug biodistribution is one way of achieving therapeutic improvements, and polymeric bilayer vesicles are one such nanosystem. Polymeric vesicles, with the ability to transport drugs or genes, are prepared in one of two ways: i) the self-assembly of amphiphilic polymers and ii) the polymerisation of monomers, following self-assembly (polymerised vesicles). There are two types of self-assembling amphiphilic polymers: water-soluble polymers derivatised with hydrophobic pendant groups and amphiphilic block copolymers. Amphiphilic alkenes and alkynes are the main compounds that are used to make polymerised vesicles. This review discusses polymer architecture fundamentals that govern the self-assembly of polymers into vesicles, the fine control on vesicle size that is achievable with polymeric vesicles and the application of the vesicles to drug delivery.
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Affiliation(s)
- Ijeoma F Uchegbu
- Nanomedicines Research Centre, Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, 27 Taylor Street, Glasgow, G4 0NR, UK.
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26
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Segota S, Tezak D. Spontaneous formation of vesicles. Adv Colloid Interface Sci 2006; 121:51-75. [PMID: 16769012 DOI: 10.1016/j.cis.2006.01.002] [Citation(s) in RCA: 180] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2005] [Accepted: 01/20/2006] [Indexed: 10/24/2022]
Abstract
his review highlights the relevant issues of spontaneous formation of vesicles. Both the common characteristics and the differences between liposomes and vesicles are given. The basic concept of the molecular packing parameter as a precondition of vesicles formation is discussed in terms of geometrical factors, including the volume and critical length of the amphiphile hydrocarbon chain. According to theoretical considerations, the formation of vesicles occurs in the systems with packing parameters between 1/2 and 1. Using common as well as new methods of vesicle preparation, a variety of structures is described, and their nomenclature is given. With respect to sizes, shapes and inner structures, vesicles structures can be formed as a result of self-organisation of curved bilayers into unilamellar and multilamellar closed soft particles. Small, large and giant uni-, oligo-, or multilamellar vesicles can be distinguished. Techniques for determination of the structure and properties of vesicles are described as visual observations by optical and electron microscopy as well as the scattering techniques, notably dynamic light scattering, small angle X-ray and neutron scattering. Some theoretical aspects are described in short, viz., the scattering and the inverse scattering problem, angular and time dependence of the scattering intensity, the principles of indirect Fourier transformation, and the determination of electron density of the system by deconvolution of p(r) function. Spontaneous formation of vesicles was mainly investigated in catanionic mixtures. A number of references are given in the review.
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Affiliation(s)
- Suzana Segota
- Department of Chemistry, University of Zagreb, Faculty of Science, Horvatovac 102a, P.O. Box 163, 10001 Zagreb, Croatia
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27
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Dentinger PM, Simmons BA, Cruz E, Sprague M. DNA-mediated delivery of lipophilic molecules via hybridization to DNA-based vesicular aggregates. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2006; 22:2935-7. [PMID: 16548535 DOI: 10.1021/la053005o] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
A scheme is presented for stabilizing hydrophobic molecules and releasing them into aqueous solution via DNA hybridization. A tetradecyl hydrophobic tail is covalently attached to synthetic oligomers, and the resulting amphiphilic molecules take up substantial amounts of orange OT and pyrene dyes in aqueous environments. The resulting structures do not affect the surface tension and are predominantly spherical as shown by light scattering and TEM, and the pyrene fluorescence is consistent with a hydrophobic environment. It is concluded that the amphiphilic DNA creates vesicular domains upon which the hydrophobic dyes reside and are stabilized in solution. Upon exposure to the complementary strand, the pyrene dye is released from the structures, showing that the scheme can be used for unlabeled or DNA-mediated drug delivery.
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Affiliation(s)
- Paul M Dentinger
- Sandia National Laboratories, P.O. Box 969, Livermore, California 94550, USA.
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Pack DW, Hoffman AS, Pun S, Stayton PS. Design and development of polymers for gene delivery. Nat Rev Drug Discov 2005; 4:581-93. [PMID: 16052241 DOI: 10.1038/nrd1775] [Citation(s) in RCA: 1910] [Impact Index Per Article: 100.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The lack of safe and efficient gene-delivery methods is a limiting obstacle to human gene therapy. Synthetic gene-delivery agents, although safer than recombinant viruses, generally do not possess the required efficacy. In recent years, a variety of effective polymers have been designed specifically for gene delivery, and much has been learned about their structure-function relationships. With the growing understanding of polymer gene-delivery mechanisms and continued efforts of creative polymer chemists, it is likely that polymer-based gene-delivery systems will become an important tool for human gene therapy.
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Affiliation(s)
- Daniel W Pack
- Department of Chemical and Biomolecular Engineering, University of Illinois, Box C-3, 600 South Mathews Avenue, Urbana, IL 61801, USA.
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29
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Cravotto G, Omiccioli G, Stevanato L. An improved sonochemical reactor. ULTRASONICS SONOCHEMISTRY 2005; 12:213-217. [PMID: 15491884 DOI: 10.1016/j.ultsonch.2004.01.002] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2003] [Accepted: 12/17/2003] [Indexed: 05/24/2023]
Abstract
The design and optimization of sonochemical apparatus are still open to advancement. Under high-intensity ultrasound reaction rates and yields are mainly influenced by the characteristics of transducer and reactor. Several useful improvements are introduced and described. In order to achieve uniformity of the acoustic field and optimal acoustic streaming in every part of the reaction vessel (a Teflon tube), the reactor can be made to rotate eccentrically around the horn axis and the probe to move alternatively up and down by a pre-determined excursion at a chosen speed. Continuous high-power irradiation is feasible without any time limit because the whole probe system is refrigerated by an oil forced-circulation circuit connected to a chiller. The apparatus can control a number of important reaction parameters: modified atmosphere, reaction temperature, tunable frequency and constant amplitude. Excellent performance was observed on several reactions, such as the chemical modification of chitosan, a poorly soluble biopolymer.
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Affiliation(s)
- Giancarlo Cravotto
- Dipartimento di Scienza e Tecnologia del Farmaco, Università di Torino, Via Giuria 9, Torino 10125, Italy.
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Azzam T, Eliyahu H, Makovitzki A, Linial M, Domb AJ. Hydrophobized dextran-spermine conjugate as potential vector for in vitro gene transfection. J Control Release 2005; 96:309-23. [PMID: 15081221 DOI: 10.1016/j.jconrel.2004.01.022] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2003] [Accepted: 01/13/2004] [Indexed: 11/19/2022]
Abstract
Dextran polysaccharide was grafted by reductive-amination with mixtures of spermine and other natural/synthetic oligoamines of two to four amine groups. The transfection efficiencies of the polycations thus obtained were assessed in various cell lines, and found to depend on the spermine contents. Higher spermine ratios of grafted oligoamines resulted in high gene expression, whereas low to negligible expressions were obtained with lower spermine contents. The effect was explained by spermine residues which exhibit altered buffering capacity in comparison to other substituted oligoamines. Hydrophobization of dextran-spermine (D-SPM) was achieved by treating the polymer with N-hydroxysuccinimide derivatives of cholesterol and fatty acids in a mixture of water/THF. The degree of hydrophobization was in the range of 1-30% mol/mol (hydrophobic moieties/primary amine) and the coupling yields were >95% as determined by (1)H-NMR. The oleate-modified D-SPM remarkably enhanced the gene expression in serum rich media, in marked contrast to unmodified D-SPM which resulted with a drastic decrease in the transfection yields. Modified D-SPM derivatives of other fatty acids and cholesterol showed improved transfection yields in comparison to unmodified D-SPM, but to a lower extent when compared to oleate modification. The improvement in cell transfection was attributed to oleate residues which probably play a role in increasing stability and uptake of polycation-DNA complexes.
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Affiliation(s)
- Tony Azzam
- Department of Medicinal Chemistry and Natural Products, Faculty of Medicine, School of Pharmacy, Hebrew University of Jerusalem 91120, Israel
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31
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Twaites B, de las Heras Alarcón C, Alexander C. Synthetic polymers as drugs and therapeutics. ACTA ACUST UNITED AC 2005. [DOI: 10.1039/b410799n] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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32
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Wang W, Qu X, Gray AI, Tetley L, Uchegbu IF. Self-Assembly of Cetyl Linear Polyethylenimine To Give Micelles, Vesicles, and Dense Nanoparticles. Macromolecules 2004. [DOI: 10.1021/ma049042o] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Wei Wang
- Department of Pharmaceutical Sciences, University of Strathclyde, 27 Taylor St, Glasgow G4 0NR, U.K., and Electron Microscopy Unit, Institute of Biomedical and Life Sciences, University of Glasgow G12 8QQ, U.K
| | - Xiaozhong Qu
- Department of Pharmaceutical Sciences, University of Strathclyde, 27 Taylor St, Glasgow G4 0NR, U.K., and Electron Microscopy Unit, Institute of Biomedical and Life Sciences, University of Glasgow G12 8QQ, U.K
| | - Alexander I. Gray
- Department of Pharmaceutical Sciences, University of Strathclyde, 27 Taylor St, Glasgow G4 0NR, U.K., and Electron Microscopy Unit, Institute of Biomedical and Life Sciences, University of Glasgow G12 8QQ, U.K
| | - Laurence Tetley
- Department of Pharmaceutical Sciences, University of Strathclyde, 27 Taylor St, Glasgow G4 0NR, U.K., and Electron Microscopy Unit, Institute of Biomedical and Life Sciences, University of Glasgow G12 8QQ, U.K
| | - Ijeoma F. Uchegbu
- Department of Pharmaceutical Sciences, University of Strathclyde, 27 Taylor St, Glasgow G4 0NR, U.K., and Electron Microscopy Unit, Institute of Biomedical and Life Sciences, University of Glasgow G12 8QQ, U.K
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Pata V, Dan N. The effect of chain length on protein solubilization in polymer-based vesicles (polymersomes). Biophys J 2004; 85:2111-8. [PMID: 14507679 PMCID: PMC1303440 DOI: 10.1016/s0006-3495(03)74639-6] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Using a mean-field analysis we derive a consistent model for the perturbation of a symmetric polymeric bilayer due to the incorporation of transmembrane proteins, as a function of the polymer molecular weight and the protein dimensions. We find that the mechanism for the inhibition of protein incorporation in polymeric bilayers differs from that of their inclusion in polymer-carrying lipid vesicles; in polymersomes, the equilibrium concentration of transmembrane proteins decreases as a function of the thickness mismatch between the protein and the bilayer core, whereas in liposomes the presence of polymer chains affects the protein adsorption kinetics. Despite the increased stiffness of polymer bilayers (when compared to lipid ones), their perturbation decay length and range of protein-protein interaction is found to be relatively long. The energetic penalty due to protein adsorption increases relatively slowly as a function of the polymer chain length due to the self-assembled nature of the polymer bilayer. As a result, we predict that transmembrane proteins may be incorporated in significant numbers even in bilayers where the thickness mismatch is large.
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Affiliation(s)
- Veena Pata
- Department of Chemical Engineering, Drexel University, Philadelphia, Pennsylvania 19104, USA.
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34
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Pata V, Ahmed F, Discher DE, Dant N. Membrane solubilization by detergent: resistance conferred by thickness. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2004; 20:3888-93. [PMID: 15969375 DOI: 10.1021/la035734e] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
The commonly held model for membrane dissolution by detergents/surfactants requires lipid transport from the inner to the outer bilayer leaflet ('flip-flop'). Although applicable to many systems, it fails in cases where cross-bilayer transport of membrane components is suppressed. In this paper we investigate the mechanism for surfactant-induced solubilization of polymeric bilayers. To that end, we examine the dissolution of a series of increasingly thick, polymer-based vesicles (polymersomes) by a nonionic surfactant, Triton X-100, using dynamic light scattering. We find that increasing the bilayer thickness imparts better resistance to dissolution, so that the concentration required for solubilization, after a fixed amount of time, increases nearly linearly with membrane thickness. Combining our experimental data with a theoretical model, we show that the dominant mechanism for the surfactant-induced dissolution of polymeric vesicles, where polymer flip-flop across the membrane is suppressed, is the surfactant transport through the bilayer. This mechanism is different both qualitatively and quantitatively from the mechanisms by which surfactants dissolve pure lipid vesicles.
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Affiliation(s)
- Veena Pata
- Department of Chemical Engineering, Drexel University, Philadelphia, Pennsylvania 19104, USA.
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